Indications for partial nephrectomy:
- Tumour in solitary kidney
- Bilateral renal tumours
- Hereditary syndromes
- Chronic kidney disease or limited renal reserve
- “Elective” – small renal mass with normal renal function and normal contra-lateral kidney
Considerations:
Hyperfiltration injury
- Renal blood flow delivered to fewer nephrons – increased glomerular capillary perfusion pressure and single nephron GFR. Over decades, nephrons injured by hyperfiltration leading to focal segmental glomerulosclerosis when the total nephron mass is reduced by > 80 %.
Renal ischaemic time
- Either regional ischaemia (selective clamping) or global ischaemia. Also warm ischaemia vs cold ischaemia (ice slush) – can tolerate longer clamp times with cooling.
- 12.5 mg intravenous mannitol and 40 mg Lasix prior to clamping may theoretically reduce ischaemic injury although not definitively proven.
Consent / complications:
Intra-op:
- Bleeding – transfusion, conversion to nephrectomy
- Conversion to nephrectomy due to inability to safely complete partial
- Pleural injury and chest transgression
- Bowel injury
- Spleen/liver/duodenum injury
- GA risks
Post-op:
- Bleeding from resection, or AVM/pseudoaneurysm – requiring IR, or return to OT +/- nephrectomy
- Urine leak requiring further procedures
- Wound issues – hernia, infection, flank bulge
- Pain and persisting neuropathic pain
- DVT/PE
Positive margins:
- 2 – 8 %
- More frequency in imperative partials, and those with adverse pathological features (pT2+, grade 3-4)
- 16 % rate of local recurrence vs 3 % for clear margins – therefore proceeding to radical nephrectomy or re-do partial will be significant overtreatment for many.
- Patients should be informed they are at higher risk for recurrence, and may need more intensive imaging surveillance
- Meta-analyses of retrospective studies are conflicting – but upstaged pT3a tumours with positive margins seem to have worse prognosis and mortality
Approach for open:
- Retroperitoneal flank approach preferred – subcostal lacks exposure to hilum and upper pole, transperitoneal risks urine leak and bleeding intraperitoneally
- Supra-11 or supra-12/tip of 12th incision ideal – supra-11 if upper pole tumour.
Technique:
- GA, lateral position with break at flank
- Above rib to avoid neurovascular bundle – continuing to edge of rectus
- Divide lat dorsi and serratus posterior behind costal margin, external and internal oblique anteriorly
- Open the lumbodorsal fascia at the tip of the rib sharply, avoiding pleura and peritoneum
- Divide TA and sweep peritoneum medially
- Expose diaphragm above – sweep/mobilise pleura superiorly
- Divide intercostal muscles as far back as needed on superior aspect of rib
- Develop the retroperitoneal space and use a fixed table retractor
- Mobilise the kidney posteriorly and laterally
- Identify the hilum – either tracing up gonadal vein or IVC – and sling the vessels
- If artery is not easily visible, may need to further mobilise and ‘flip’ kidney to identify and sling from behind
- Undress the kidney, opening Gerota’s and mobilising peri-nephric fat over tumour to expose – can use Rampley’s on the fat
- Score the tumour with diathermy and ultrasound the get a feel for the extension
- Bulldog clamp on artery +/- vein (or use slings; or use hand to compress the kidney)
- Excise tumour – can fracture the plane with Metz, or use diathermy
- Assistant using Frazier suckers
- Close any collecting system breach with 4-0 PDS
- Overrun the base with 3-0 stratafix or V-loc
- Clamps off
- Fibrillar and Floseal to base and compress with a wet Raytec for a few minutes
- Oversew any bleeding points figure of 8 3-0 PDS
- Sliding clip renorrhaphy second layer – 1-vicryl – Hem-o-lok on tail – through each parenchymal edge +/- including perinephric fat – clip on other end and snug down, careful not to pull through
- Cover with perinephric fat
- Drain
- Mass closure or closure in 2 layers – can unbreak the table and use interrupted 0 vicryls if needed
Bleeding:
- If brisk arterial bleeding on parenchymal incision – either missed artery or dodgy clamp
- If ongoing parenchymal venous bleeding – can take off venous clamp to reduce engorgement, or compress kidney with hand
- Consider haemostatic agents like Tachosil
Excise 11th rib:
- If needed – scrape periosteum off bone with periosteal elevator / osteotome then circular rib stripper, pulling periosteum anteriorly to tip of rib
- Use rib cutter with blade as far posterior as needed
- Bone wax if needed for bleeding cut edge
Pleural injury:
- Repair with 3-0 PDS (monofilament given delicacy) – tie on Valsalva / positive pressure expiration
- Consider drain if large complex injury
Urine leak:
- Will generally settle with time and leaving drain – sit tight if no infection, and not single kidney leaking
- If forced to place stent, need catheter as well to minimise reflux